In a liquid crystal display, both surfaces of a liquid crystal cell in which a liquid crystal is retained are generally provided with a polarizer. Conventionally, in order to visually compensate for retardation caused by birefringence of the liquid crystal cell in a front direction and an oblique direction, a birefringent layer is disposed between the liquid crystal cell and the polarizer. As this birefringent layer, a negative birefringent layer that is obtained by aligning cholesteric liquid crystal molecules on an alignment substrate and whose refractive indices (nx, ny, nz) satisfy a negative uniaxiality “nx=ny>nz” usually is used. The refractive indices (nx, ny, nz) respectively indicate refractive indices in three axial directions in the birefringent layer. The axial directions of the refractive indices (nx, ny, nz) in the birefringent layer are indicated specifically by arrows in a schematic view of FIG. 2. As mentioned above, the refractive indices nx, ny, nz respectively indicate refractive indices in an X-axis direction, a Y-axis direction and a Z-axis direction. As shown in the figure, the X-axis direction is an axial direction exhibiting a maximum refractive index within the plane, the Y-axis direction is an axial direction perpendicular to the X axis within the plane, and the Z-axis direction is a thickness direction perpendicular to the X axis and the Y axis.
As such a birefringent layer, a compensation plate obtained by applying a coating solution of a liquid crystal polymer onto an alignment substrate so as to align the liquid crystal polymer in a cholesteric manner has been disclosed (see Japanese Patent 2660601, for example). More specifically, an example thereof can include a birefringent layer constituted by a cholesteric liquid crystal polymer in which the product of a helical pitch of a cholesteric structure and a refractive index is not larger than 400 nm, and this birefringent layer compensates for a visual angle (see JP 3(1991)-67219 A, for example). JP 3(1991)-67219 A discloses that, in order to achieve a property that the liquid crystal polymer exhibiting a cholesteric liquid crystalline phase oriented substantially in parallel with the substrate is substantially isotropic with respect to visible light within a flat surface, its cholesteric pitch has to be shorter than a visible light wavelength (about 400 nm to 800 nm). Also disclosed is that, in order to prevent the undesired coloration caused by selective reflection owing to the cholesteric structure of the liquid crystal polymer, the product of the refractive index of a birefringent phase and the helical pitch has to be shorter than 400 nm, for example.